First appearance of Special Agent Clark Palmer.
The Defense Security Service, originally known as the Defense Investigative Service and as of 2019 is now called the Defense Counterintelligence and Security Agency (DCSA), is the security investigative agency of the Department of Defense (DoD). They are tasked with conducting personnel security investigations, industrial security and conducting security and awareness training for federal law enforcement agencies. DCSA assists and conducts investigations of security breaches for the US military, DoD, most federal law enforcement agencies, and government contractor companies. The DCSA is also tasked with conducting background checks and investigations, 95% of the background investigations ordered by the federal government are done by the DCSA. The DCSA also is responsible for ensuring the personnel and facility security of over 10,000 private government contractors. Although investigating the crash of a military aircraft is not something that would fall under DCSA jurisdiction.
Some of this episode's plot makes use of the rumors and sightings regarding the Northrop Grumman B-2 Spirit stealth bomber when it was still under development, in fact the unidentified aircraft in this episode has a similar profile to the B-2. Development on the B-2 began in the early 1980's, and while the project was classified top secret word leaked out to the general public that the government was developing some type of new advanced stealth bomber, some rumors even saying that it was using reverse engineered technology from the UFO that crashed in Roswell. The components for the prototype were manufactured in an old, repurposed Ford automobile assembly plant in Pico Rivera, California, they were then shipped to an airfield in Palmdale, California for assembly. The first public display of the B-2 was there in 1988, but in the year prior to that people in the desert around Palmdale and Edwards Air Force Base reported seeing a black, triangle shaped UFO in the sky. While the details of the early assembly and testing of the B-2 remain classified rumors from the past 30 years indicate that the initial test flights for the B-2 were likely done at Edwards AFB, as it is only 39 miles from the assembly location in Palmdale. Rumors also suggest the B-2's weapons and bombing systems were tested at the live-fire exercise testing range at the nearby Marine Corps Air Ground Combat Center in 29 Palms, where this episode takes place at.
The exterior shots of the Bradenhurt Corporation building were filmed at the Mann Biomedical Park building in Santa Clarita, California. The building is home to a biomedical research company and since the building has a somewhat unique "futuristic" look it has been used as a filming location in a number of TV series and movies. A few examples are The X-Files (1993), The Mentalist (2008) and Furious 7 (2015).
The U.S. military was actually developing a type of non-lethal pulse weapon that Bud describes to Colonel Barret at the time this episode was filmed. Labeled the Long-range Acoustic Device (LRAD) it uses a high frequency sonic pulse to incapacitate groups of people for crowd control. It can be mounted on a helicopter, and starting in 2003 was installed on a number of Navy warships to help ward off pirates and other potential hostiles on small watercraft when lethal force is not needed or desired. On naval vessels it also has the added benefit of acting as a type of long range hailing device, in essence an extremely powerful loudspeaker that allows a vessel to verbally communicate with another vessel that is either unable or unwilling to respond to radio hails.